Papyrus Bridge

PrismaUI_F4 automatically injects window.prisma into every view before OnDomReadyCallback fires. Papyrus modders can read and write live game data directly from JavaScript — no C++ plugin required.

Overview

Every HTML view created by any plugin (V1 or later) gets window.prisma for free. You don’t request it, configure it, or install anything extra. If PrismaUI_F4 is installed, window.prisma is there.

// window.prisma is available as soon as DOM ready fires.
// No RequestPluginAPI, no view handle, no C++.

const damage = await prisma.getProperty("MyMod.esp", "800", "MyMod_QuestScript", "DamageScale");
prisma.setProperty("MyMod.esp", "800", "MyMod_QuestScript", "DamageScale", 2.5);

const diff = await prisma.getGlobal("MyMod.esp", "801");
prisma.setGlobal("MyMod.esp", "801", 3.0);

Methods

prisma.getGlobal(esp, formId)

Reads a TESGlobal form’s float value.

Returns: Promise<number | null>

prisma.setGlobal(esp, formId, value)

Writes a TESGlobal form’s float value. Fire-and-forget — returns undefined.

prisma.getProperty(esp, formId, scriptName, propName)

Reads a Papyrus Auto property on a script attached to a form.

Returns: Promise<number | boolean | null>

prisma.setProperty(esp, formId, scriptName, propName, value)

Writes a Papyrus Auto property. Fire-and-forget — returns undefined. The value is coerced to the property’s declared type (float, int, or bool) automatically.

Form ID format

formId is the local form ID — strip the file-index byte.

ESL forms use the same convention. PrismaUI_F4 resolves the ESL prefix automatically via TESDataHandler::LookupForm.

Null return

Both read methods return null (never throw) when:

• The plugin is not in the active load order
• The form ID does not exist in that plugin
• The form exists but is the wrong type (not TESGlobal, or script not attached)
• The property name is not found or not declared Auto
• The Papyrus VM is not yet ready — always call after kPostLoadGame

const val = await prisma.getGlobal("MyMod.esp", "800");
if (val === null) {
  // plugin absent, form not found, or VM not ready
  return;
}

Supported property types

Full example

Papyrus script (Creation Kit):

Scriptname MyMod_QuestScript extends Quest

float Property DamageScale  = 1.0   Auto
bool  Property HardcoreMode = false Auto
int   Property Difficulty   = 1     Auto

Attach this script to a Quest form. Quest forms are the most reliable host — they persist across cell changes and the Papyrus VM always has them loaded.

HTML view:

<script>
  async function loadSettings() {
    const dmg  = await prisma.getProperty("MyMod.esp", "800", "MyMod_QuestScript", "DamageScale");
    const hard = await prisma.getProperty("MyMod.esp", "800", "MyMod_QuestScript", "HardcoreMode");

    if (dmg  !== null) document.getElementById("damage").value   = dmg;
    if (hard !== null) document.getElementById("hardcore").checked = hard;
  }

  function saveDamage(val) {
    prisma.setProperty("MyMod.esp", "800", "MyMod_QuestScript", "DamageScale", parseFloat(val));
  }

  function saveHardcore(checked) {
    prisma.setProperty("MyMod.esp", "800", "MyMod_QuestScript", "HardcoreMode", checked);
  }
</script>

Requirements

• Quest form host — use a persistent Quest form, not a cell-local reference
• After kPostLoadGame — the Papyrus VM is not ready before the game loads; settings menus opened in-game are always safe
• PrismaUI_F4 installed — window.prisma is injected by the framework; without it the object is undefined

Threading model

JS calls to window.prisma fire on the Ultralight render thread. PrismaUI_F4 marshals all RE:: game-data access to the game thread via F4SE::GetTaskInterface()->AddTask internally. Responses are delivered back to JS as Promise resolutions via _prismaResponse. This is transparent — from JS the API is just async functions.